new Promise((resolve, reject) => {
    setTimeout(() => {
        resolve('hello')
    }, 10)
}).then(data => {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            resolve(data + 'lagou')
        }, 10)
    })
}).then(data => {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log(data + 'i ♥ y')
        }, 10)
    })
})
